Material handling system

ABSTRACT

A fork lift truck, in preferred form, has a base frame, a rack frame, a mast, and an operator&#39;&#39;s platform. There is no center section at the bottom of the vehicle. The assembly is held together at the top with an arch formed by the mast and the truck rack frame. Two tie bars, one on each side on the vehicle, tie the frame together near the bottom. The tie bars are adjustable for height. A rigid mast supports an assembly which includes a carriage having a pivot-and-slide mechanism and a reach mechanism on which the fork is mounted. The pivot-and-slide mechanism permits the reach mechanism and its fork to be rotated and to be slidingly moved transversely from one side to the other. Thus, the mechanism permits the forks to deposit or to withdraw a load in both forward and side positions. An operator&#39;&#39;s platform is mounted on the truck forward of the mast.

I United States Patent 1 n 1 3,727,778

Hollenbach 51 Apr. 17, 1973 MATERIAL HANDLING SYSTEM PrimaryExaminer-Robert G. Sheridan Assistant Examiner-Lawrence J. Oresky [75]Inventor. Edwin A. Hollenhach, Paola, Pa. Attorney-Hem N. Paul Jr. etal- [73] Assignee: Drexel Industries, Inc., Horsham,

Pa. 57 ABSTRACT [22] Filed: July 8, 1971 A fork lift truck, in preferredform, has a base frame, a rack frame, a mast, and an operator'splatform. [21] Appl' No" 160,600 There is no center section at thebottom of the vehicle. The assembly is held together at the top with anU-S. Cl. R, A, arch fomed the ast and the truck rack frame 34 Two tiebars, one on each side on the vehicle, tie the [51] Ilgt. Cl- ..B60p farne together near the The tie bars are ad- [58] Field of Search..2l4/75 R, 75 H, 75 G, justable f height A rigid mast supports anassembly 214/ 75 730 which includes a carriage having a pivot-and-slidemechanism and a reach mechanism on which the fork Refel'em Cited ismounted. The pivot-and-slide mechanism permits TBS NTS the reachmechanism and its fork to be rotated and to UNITED STA FATE be slidinglymoved transversely from one side to the 3,190,473 6/1965 Loef ..214/730other. Thus, the mechanism permits the forks to 3,521,779 7/1970 Warrenet a] ..2l4/730 d it or t withdraw a load in both forward and side3,504,810 4/1970 Walda ..2l4/75 R posifions. An operators platform ismounted on the truck forward of the mast.

3 Claius, 6 Drawing Figures so 41+ so a) l PATENTED APR 1 7191s SHEET 1OF 4' INVENTOR. Edwin A. Hollenbqch Mv-M ATTORNEYS.

PATENTEDAPR 1 7197s SHEET 2 BF 4 T i i 2 4 U 4 u 86- INVENTOR.

3 Edwin A. Hollenboch ATTORNEYS- PATENTEDAPR 3.727. 778

SHEET 3 OF 4 INVENTOR. Edwin AQHOI Ien buch BY W+M ATTOR NEYS PATENTED11915. 3; 727. 778

SHEET 4 OF 4 INVENTOR.

Edwin A. Hollenbuch BY fax WW5 ATTORNEYS.

MATERIAL HANDLING SYSTEM BACKGROUND OF THE INVENTION This inventionrelates to material handling vehicles and systems, and particularly tofork lift trucks and fork lift truck systems.

It is, of course, well known to use fork lift trucks for stackingpalletized loads. However, prior art fork-lift material-handling truckshave not been sufficiently flexible, and a good deal of time is lost inunnecessary travel and motions.

SUMMARY OF THE INVENTION An important object of the present invention isto provide a fork-lift material-handling system in which one fork liftvehicle does the work of up to five prior art vehicles.

Another object is to provide a fork-lift material-handling system inwhich the travel time of the fork lift vehicle is greatly reduced incomparison with prior art fork-lift material-handling systems.

A further object is to provide a fork-lift material-handling systemcapable of handling loads stacked two deep in floor racks on each sideof the aisle.

Another object is to provide a material-handling system havingflow-through characteristics, with material being received at one endand shipped out at the other end.

A more specific object is to provide a fork lift truck having a truckrack on which the palletized loads are carried, and wherein any palletmay be randomly selected.

A broad object is to provide a material handling system havingflow-through characteristics which is applicable to both fork lift floorvehicles and overhead rail crane stackers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of oneform of fork lift vehicle embodying the present invention.

- F IG. 2 is a diagrammatic plan view to illustrate how the fork lifttruck of the present invention may be employed to carry out itspurposes.

FIG. 3 is an elevation view, partly broken and partly in section,illustrating a modified version of fork lift vehicle according to thepresent invention.

FIG. 4 is a view looking along the line 4-4 of FIG. 3.

FIG. Sis a view looking along the line 5-5 of FIG. 3.

FIG. 6 is a side elevational view of a presently preferred form of forklift vehicle in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is aperspective view of a fork lift vehicle embodying one form of thepresent invention. FIG. 6 is a side elevational view of a presentlypreferred form of fork lift vehicle embodying the present invention. Theprincipal difference between the vehicles shown in FIGS. 1 and 6 is thatin the vehicle of FIG. 6 the truck chassis has no center section. Thevehicle of FIG. 6 is tied together at the top by an arch 130 formed bythe top of the mast 30 and the top of the truck rack 50. The lowerportion of the truck is tied together at the center by a pair of tiebars 70, one on each side of the chassis.

The tie bars are adjustable vertically as to position. In otherrespects, the vehicle of FIG. 6 is similar to that shown in FIG. 1. Thevehicle of FIG. 1 will first be described.

The vehicle shown in FIG. 1 includes a chassis 10 having at one end,arbitrarily designated the front end, a pair of front wheels 11 and atthe other or rear end a pair of rear wheels 12. At least one of thepairs of wheels is ordinarily steerable. An operators control position20, evidenced in FIG. 1 by the steering wheel 21, is provided at therearward end of the chassis. The

vehicle is provided with known forms of power drive and controlmechanisms for driving and controlling the vehicle and for operating thefork lift assembly.

At the forward end of the chassis 10 there is provided, in accordancewith the present invention, a rack in the form of a columnar structureor tower 50. Rack tower 50 contains a plurality of individualmaterialreceiving compartments arranged one above the other. In FIG. 1,six such individual compartments are shown, identified by referencenumerals 51 through 56, wherein 51 is the bottom-most compartment and 56is the upper-most. Each of the compartments 51-56 is provided with apair of angle support members 57, one at each side of the compartments.These angle members 57 function as side rails for supporting the pallets58 bearing the loads 59. Windows 60 may be provided in the side walls ofthe rack tower 50 to facilitate identification of the palletized loadsin the compartments.

Immediately in front of the operator's control position 20, and spacedrearwardly from the rack tower 50, is a mast lift assembly 30. The mastlift assembly includes, among other things, a pair of stationaryvertical guide channels or rails 31, movable guides 32 which areslidable up and down in the stationary vertical guide channels 31, and acarrier frame 33 which is movable up and down relative to both the guiderails 31 and the guides 32. The carrier frame 33 carries the lift fork34. A pair of chains 35 are shown trained over a pair of pulleys 38carried at the upper end of a piston 36 of a hydraulic lift cylinder 37.One end of the chains 35 is fixed to the carrier frame 33 while theother end is fixed to the stationary guide rails 31. Thus, when thepiston 36 is extended, the carrier frame 33 is lifted through a distanceequal to twice that of the distance through which the piston 36 ismoved. The mast lift assembly 30 used in the vehicle of the presentinvention may be a well known form of mast lift assembly, and need notbe further described.

The fork 34 is supported on a scissor-like extension or reach mechanism40 which in turn is supported on a transverse carriage 41 which issupported on the elevatable carrier 33. Carriage 41 is movable back andforth transversely on the elevatable carrier 33. The extension or reachmechanism 40 is pivotably mounted on the transversely movable carriage41, and is pivotable through Thus, the fork 34 may be directed laterallyin either one of the two side directions, i.e., either toward the leftor toward the right side of the chassis. Or, the fork 34 may be directedforwardly toward the rack tower 50. The pivotally mounted scissors-likeextension or reach mechanism 40 used in the fork lift vehicle of thepresent application is known in the art and need not be described indetail. Suitable reach mechanisms may, for example, be obtained from TheRaymond Corporation, Greene, New York, or from Long Reach Manufacturing,a division of Anderson-Clayton Company (Inc.), Houston, Texas, or fromCascade Corporation, Portland, Oregon, or from others.

The vehicle shown in FIG. 6 is generally similar to that of FIG. 1except that there is no center section at the bottom of the vehicle. Thetruck assembly is held together at the top by means of an arch 130formed by the mast 30 and rack tower 50. Two tie bars 70, one on eachside of the vehicle, are located near the bottom, preferably at theheight or level of the first rack cross frame. The tie bars 70 areadjustable for height. This arrangement, as compared with the vehicleshown in FIG. 1, permits the carriage assembly and the forks 34 to reachthe floor on both sides of the vehicle and to handle loads which rest onthe floor.

Another modification is illustrated in FIG. 3. The truck of FIG. 3differs from these of FIGS. 1 nd 6 primarily in that the truck of FIG. 3is not equipped with a scissors extension or reach mechanism 40, but isinstead provided with a pull-together mechanism. Like the trucks ofFIGS. 1 and 6, the truck of FIG. 3 includes a transverse carriagemounted on an elevatable carrier 33. The fork 34 is mounted on thecarriage 41 to be pivotable through 180 so that the fork 34 may bedirected either to the right or to the left of the chassis and forwardlytoward the compartments in the rack tower 50.

When facing forwardly toward the rack tower 50, the load on the fork 34may be deposited in a selected compartment of the rack tower 50 (or aload may be removed from a compartment of the rack tower 50) bypulling-together the two ends of the truck chassis, i.e., by moving therack tower end of the truck closer to the mast assembly. The means fordoing this will now be described.

In the chassis of FIG. 3, the rack tower section of the truck isseparated from the mast assembly section except for a pair of connectingracks 71. The forward ends of the racks 71 are fixed to the rack towersection. The rearward ends of the racks are free to move relative to themast assembly section of the truck. The mast assembly section isprovided with a pair of fixed racks 75, one on each side of the vehiclelocated in the same vertical planes as the racks 7]. Cylinders 76 havingpistons 77 carry at their forward ends gears 78 which are adapted toengage the teeth of the racks 71 and 75. It will be seen from FIG. 3that, when the pistons 77, one on each side of the vehicle, areretracted, the gears 78 will be caused to move counterclockwise, asviewed in FIG. 3, thereby causing the rack tower section 50 and the mastassembly section 30 to move toward each other, thereby causing the fork34 to enter into one of the compartments of the rack tower 50. Since themodified form of the vehicle illustrated in FIG. 3 does not have anextension-scissors reach mechanism 40, the form of vehicle shown in FIG.3 is not capable of handling loads which are located two deep in thefloor stacks.

The modified truck in FIG. 3 is illustrated as having several featureswhich may also be applied to the fork lift trucks of FIGS. 1 and 6.Where the warehouse ceiling is high, the mast lift assembly 30 may be sotall as to make stabilization desirable. In such case,- a track or rail81, illustrated in FIGS. 3 and 4, may be secured to the ceiling beams80, and the upper end of the mast assembly 30 may be provided withbearings 82 which ride along the rail 81 thereby providing the necessarystabilization of the tall mast assembly 30. In some cases, it may alsobe desirable to provide an equally high rack tower 50 and to alsoprovide the rack tower 50 with bearings for riding along the guide rail81.

An alternate form of stabilization is illustrated in the vehicle of FIG.6 where the arched portion 130 at the top of the vehicle is providedwith side stabilization rollers for bearing against the floor racks. Thestabilization rollers are identified 185.

In some cases, in order to relieve the operator of the necessity ofsteering the truck up and down the aisles, the chassis of the truck maybe provided with side guide rollers 85 just above the floor level, suchas are illustrated in FIG. 5 of the drawing. These side guide rollers 85may engage rails 86 which may be provided along the sides of the aislesat the floor level.

OPERATION The fork lift vehicle provided by the present invention, apreferred form of which is illustrated in FIG. 6, and other forms ofwhich are illustrated in FIGS. 1 and 3, enables the material to behandled on a flow-through basis, with receiving at one end and shippingor delivery at the other end. This system will now be described withreference to FIG. 2. FIG. 2 illustrates a fragment of a be provided atthe end of each aisle. Such feed racks may be capable of a warehouse.Three stacking areas are shown identified as A, B and C. Each of theareas is assumed to consist of four rows of palletized loads. Theoutside row of each area borders along a narrow aisle. The aisles areidentified as a, b, c and d. As seen, the aisles extend from a receivingarea, identified by the letter R, to a shipping or delivery area,identified by the letter D. The product may be received and handled by astandard truck in area R. Sorting into a feed rack may be capable ofholding vertically the same number of pallets as the rack of the forklift truck is capable of handling, so as to match positions with thetruck racks. The feed truck is driven up to the truck rack of the forklift truck, and the truck racks are loaded, either by power or gravityfeed. This permits simultaneous loading of all levels of the truck rack.

The fork-lift truck is driven down an aisle from left to right, asviewed in FIG. 2. En route, it may deposit and/or pick up palletizedloads in a variety of sequences. For example, assume that all six of thecompartments 51-56 of the vehicle rack are filled with palletized loadsat the beginning of its travel from area R. This should be the case ifno load is to be picked up from the floor stacks before a load is to bedeposited. If, on the other hand, a palletized load is to be picked upfrom the floor stacks before a palletized load on the truck isdeposited, the truck should, of course, have a vacant compartment in itsrack at the beginning of its run. In general, the number of vacantcompartments in the truck rack at the beginning of a run shouldcorrespond to the number of floor-stack loads which are to be picked upen route to the delivery area D which exceed the number of palletizedloads which are to be deposited before reaching the delivery area D.

In FIG. 2, a truck T1 is shown entering aisle b. A second truck T2 isshown in aisle c picking up (or depositing) a two-deep palletized loadin the second row of area C. The palletized load which had been in thefirst row of area C has been picked up and deposited temporarily in oneof the rack compartments of the rack tower 50 of the truck T2. After thetwodeep load is picked up from (or deposited in) the second row of areaC, the palletized load which had been in the first row will be returnedfrom the truck T2 to its position either in the first row or in the nowvacant spot in the second row. In FIG. 2, a third truck T3 is shown inaisle d depositing a load in (or picking up a load from) the fourth rowof area C. It is believed that from the description and explanationgiven thus far, the versatility of the operation which is available willbe apparent.

To summarize, in the system proposed by the present invention, using afork lift truck of the type or types shown in the present application,any pallet may be randomly selected on the truck rack 50. The reachmechanism 40 will extend forward and the fork 34 will lift the palletfrom the rack 50. The load is then withdrawn from the rack by closingthe reach mechanism. The loaded fork is then rotated to either one sideor the other, as selected. The loaded fork is then slidingly transferredto the side on the transverse carriage 33. This permits unloading (orloading) in the front or one-deep position of the floor rack. If thetwo-deep or second position in the floor rack is involved, the reachmechanism 40 is extended and the load placed at (or picked up from) thesecond depth. The motion is reversed to withdraw a load from the floorracks.

Whenever a load has been removed from the truck rack 50, the space madeavailable in the truck rack may now receive a load from the floor rackfor delivery at the shipping or delivery end D. If two spaces are keptopen on the truck rack 50, a one-deep" or front load from the floor rackmay be stored in the one open space, and the two-deep or second loadfrom the floor stack may now be withdrawn and placed in the second opencompartment in the truck rack 50. The first or original load may then bereturned to the second position in the floor rack, and the second loadon the truck may be delivered to the shipping or delivery area D.

It will be seen that the equipment shown and described permits effectivehandling of loads which are two deep in the floor aisle, withoutexcessive traveling back and forth on the part of the truck. Long,narrow aisles (up to 600 feet) now become feasible because multipleloads can be handled without doubling back and forth or passing othertrucks in the aisles. The material-handling system described eliminatesapproximately two-thirds of the travel time presently used by fork liftvehicles for placing and withdrawing loads using conventional prior artfork lift equipment.

In the proposed system, one vehicle and its driver may replace up tofive prior art vehicles and their drivers. Thus, both equipment andmanpower are saved. The reduced travel time permits one operator to dothe work of up to five operators in about the same time. The fact thatloads stored two deep in the floor aisles may now be handled efficientlypermits savings on total rack space requirements. No passing of true sin the narrow aisles is required under the presently described proposedmethod. Moreover, with the vehicle shown in FIG. 6, loads can be handledfrom the floor all the way to the top of the rack.

Stability of the truck, both longitudinally and transversely, may bemaintained by either over-head guides or roller stabilizers at the floorlevel or at the top of the assembly. 7

It is noted that the material handling system proposed in the presentapplication is applicable to crane stackers as well as to fork lifttrucks, since it is immaterial whether the vehicle be supported bywheels which ride on the floor of the warehouse or on overhead rails.

In the claims which follow the term fork lift vehicle" is intended toinclude elevatable fork vehicles which are supported on overhead railsas well as elevatable fork vehicles which are supported on the floor.

What is claimed is:

1. A material handling fork lift vehicle for handling palletized loads,said vehicle comprising:

a. a wheeled chassis;

b. a rack tower on said chassis at one end thereof;

c. said rack tower including a plurality of loadreceiving compartmentsarranged vertically one above the other;

. a mast and an elevatable forklift assembly on said mast and spacedfrom said rack tower;

e. said fork lift assembly including a fork and means for pivoting saidfork through to direct said fork toward either side of said chassis orstraight ahead towards said rack tower;

f. means for effecting relative movement between said fork and said racktower for moving said fork into and out of any selective one of saidrack tower compartments,

g. said means for effecting relative movement between said fork and saidrack tower including means or contracting and expanding said chassis tomove said rack tower and fork toward and away from each other, said forkbeing non-extensible relative to said mast;

. in the expanded condition of said chassis the space between the mastand the rack being greater than the length of the fork, the contractionof the chassis causing the fork to enter the rack.

2. Apparatus according to claim 1 wherein said means for contracting andexpanding said chassis include rack and pinion means at each side ofsaid chas- SIS.

3. Apparatus according to claim 2 wherein said rack and pinion meansinclude:

a. a first pair of racks having one end fixed to said rack tower at eachside of said chassis, said racks projecting toward said mast;

b. a second pair of racks fixed to said mast;

c. a pinion in mesh with racks of said first and second pairs at eachside of said chassis;

d. piston means for pulling and pushing said pinions.

I! I il l Il

1. A material handling fork lift vehicle for handling palletized loads,said vehicle comprising: a. a wheeled chassis; b. a rack tower on saidchassis at one end thereof; c. said rack tower including a plurality ofload-receiving compartments arranged vertically one above the other; d.a mast and an elevatable fork lift assembly on said mast and spaced fromsaid rack tower; e. said fork lift assembly including a fork and meansfor pivoting said fork through 180* to direct said fork toward eitherside of said chassis or straight ahead towards said rack tower; f. meansfor effecting relative movement between said fork and said rack towerfor moving said fork into and out of any selective one of said racktower compartments, g. said means for effecting relative movementbetween said fork and said rack tower including means for contractingand expanding said chassis to move said rack tower and fork toward andaway from each other, said fork being non-extensible relative to saidmast; h. in the expanded condition of said chassis the space between themast and the rack being greater than the length of the fork, thecontraction of the chassis causing the fork to enter the rack. 2.Apparatus according to claim 1 wherein said means for contracting andexpanding said chassis include rack and pinion means at each side ofsaid chassis.
 3. Apparatus according to claim 2 wherein said rack andpinion means include: a. a first pair of racks having one end fixed tosaid rack tower at each side of said chassis, said racks projectingtoward said mast; b. a second pair of racks fixed to said mast; c. apinion in mesh with racks of said first and second pairs at each side ofsaid chassis; d. piston means for pulling and pushing said pinions.